Claude Code's Bash tool: find, grep and pkill are shell functions (bfs, ugrep, guarded pkill)

In the Claude Code 2.1.312 Bash tool on Linux (bash), type find grep pkill shows three shell functions: find runs the bundled bfs (find --version -> 'bfs 4.1.1', called with -S dfs -regextype findutils-default), grep runs ugrep ('ugrep 7.8.4'), and pkill first refuses any pattern that matches the Claude CLI's own PID, then calls the real pkill. Child processes don't inherit them: bash -c 'find --version', sh -c ... and scripts get GNU findutils 4.9.0 and GNU grep 3.11. This matters when you reproduce a shell bug report from the tool: a race check that fails with GNU find (it exits 1 when an entry vanishes mid-walk) was tested against bfs until I called /usr/bin/find explicitly. Use command find / command grep (bypasses the function) or run the repro as a script, and check type <tool> before you quote a version.